Method for extracting natural juice of ligneous plant material, device for carrying out said method and use of said method in the production of dried ligneous plants material

Abstract

The invention relates to a method for extracting the natural juice of ligneous plant material, a device for carrying out said method and the use of said method in the production of dried ligneous plant material. The method for extracting the natural juice of ligneous plant material comprises the following: a pressurization step in which a sealed enclosure containing the plant material is pressurized, whereby the pressure thereof is greater than that of the atmosphere; a stage in which saturating water vapor is created or injected; a stage in which the plant material is heated to the core by means of electromagnetic waves; a step in which the liquid exudates from said plant material are gravitationally recovered.

What is claimed is:  
     
       1. A process for extracting natural liquor from ligneous plant matter characterised in that it comprises: 
       a stage of pressurisation above atmospheric pressure of a sealed enclosure containing the matter;  
       a stage of creation or injection of saturated water vapour;  
       a stage of heating to the core of the plant matter by electromagnetic waves;  
       a stage of gravitory recovery of the liquid exudations emerging from the processed plant matter.  
     
     
       2. A process for extracting natural liquor from ligneous plant matter according to  claim 1 , characterised in that the recovery stage may be executed at least in part during the stage of creation or injection of saturated water vapour. 
     
     
       3. A process for extracting natural liquor from ligneous plant matter according to  claim 1 , characterised in that the total pressure is between 1.5 and 9.6 bars. 
     
     
       4. A process for extracting natural liquor from ligneous plant matter according to  claim 1 , characterised in that the total pressure is adapted as a function of the plant matter processed and of the vapour temperature surrounding this matter. 
     
     
       5. A process for extracting natural liquor from ligneous plant matter according to  claim 1 , characterised in that the electromagnetic wave power is modulated to allow the matter to be heated to the core, which is from a few tenths of a degree to a few degrees above the vapour temperature resulting from the total pressure selected. 
     
     
       6. A process for extracting natural liquor from ligneous plant matter according to  claim 1 , characterised in that the volume of water at atmospheric pressure and external ambient temperature is equivalent to two to four times the volume of air contained in the enclosure in the same conditions. 
     
     
       7. A process for extracting natural liquor from ligneous plant matter according to  claim 6 , characterised in that the volume necessary for the saturated vapour pressure, for the operational temperature selected, is about three times the air mass contained in the enclosure at ambient temperature. 
     
     
       8. A process for extracting natural liquor from ligneous, plant matter according to  claim 1 , characterised in that the electromagnetic wave frequency is adapted to the size of the mass of plant matter to be processed in the enclosure, so as to allow the waves to penetrate right to the core of the plant mass to be processed. 
     
     
       9. A process for extracting natural liquor from ligneous plant matter according to  claim 1 , characterised in that the wave frequency is between 13 MHz and 2450 MHz. 
     
     
       10. A process for extracting natural liquor from ligneous plant matter according to  claim 1 , characterised in that it comprises a stage of draining off the liquors out of the enclosure under pressure during or in the course of the extraction process. 
     
     
       11. A process for extracting natural liquor from ligneous plant matter according to  claim 9 , characterised in that it comprises a stage of adaptation, after the liquors have been drained off, of the conditions of total pressure, temperature and microwave control power to facilitate the penetration into the wood of additive products injected into the enclosure. 
     
     
       12. A device allowing the process to be implemented, characterised in that it is constituted by a sealed enclosure resistant to pressure by a plurality of windows made of quartz or of any other wave suiting material with an electromagnetic wave generator placed near each window, so as to emit the waves transversely to the mass of plant material placed in the enclosure, a device for generating saturated water vapour at pressure above atmospheric pressure so as to create or inject a saturated water vapour pressure at a vapour temperature and at a total pressure determined as a function of the plant to be processed. 
     
     
       13. A device according to  claim 12 , characterised in that it comprises pressurised air circulation means. 
     
     
       14. A device according to  claim 12 , characterised in that the vapour generator device allows pressurised vapour to be injected at the pre-set vapour temperature and total pressure. 
     
     
       15. A device according to  claim 14 , characterised in that the vapour generator device comprises in the enclosure a receptacle for receiving a quantity of water corresponding to two to four times the air mass contained in the enclosure at external ambient temperature and means of heating this water to bring it to the vapour state. 
     
     
       16. A device according to  claim 15 , characterised in that the heating means are controlled by a device, which measures the total pressure prevailing within the enclosure allowing the water heating to be interrupted when the desired pressure is reached. 
     
     
       17. A device according to  claim 12 , characterised in that the enclosure comprises a device for recovering liquors by run-off and/or gravity of the liquors extracted from the matter. 
     
     
       18. A device according to  claim 17 , characterised in that the liquor recovery device communicates via a sluice with the outside of the enclosure, said sluice being controlled in order to carry out partial draining of liquor while the machine is operating. 
     
     
       19. A device according to  claim 12 , characterised in that the mass of plant matter processed in a liquor extraction operation is constituted by a plant oil type and the pressure and temperature conditions are determined as a function of the plant oil type in order to extract the worthwhile active constituents in the best conditions. 
     
     
       20. A device according to  claim 19 , characterised in that the plants are processed with bark or without bark straight from felling. 
     
     
       21. A device according to  claim 19 , characterised in that the plants are the branches and leaves resulting from pruning. 
     
     
       22. A natural liquor obtained by the process according to  claim 1 , characterised in that it is obtained from the processing of ligneous plant matter.